The present disclosure relates to a workpiece manufacturing apparatus.
The workpiece manufacturing apparatus disclosed in Japanese Patent No. 5423302 manufactures workpieces by punching out the workpieces from an unprocessed material.
The apparatus has an upper die assembly and a lower die assembly, which are arranged on opposite sides of the unprocessed material. The upper die assembly and the lower die assembly move relative to each other in the approaching direction to be clamped and move relative to each other in the direction away from each other to be opened. One of the upper and lower die assemblies is referred to as a first die assembly, which is provided with a punch for punching out a workpiece from the unprocessed material in the clamped state, and the other die assembly is referred to as a second die assembly, which is provided with an ejector capable of approaching and moving away from the first die assembly. The ejector is positioned in correspondence with the punch in the first die assembly and is urged toward the first die assembly by a spring provided in the second die assembly.
In the above-described workpiece manufacturing apparatus, the unprocessed material between the clamped upper and lower die assemblies is held between the punch and the ejector. When the punch punches out the workpiece from the unprocessed material in this state, the punched out workpiece fits into the second die assembly and the ejector is retracted into the second die assembly. The manufacturing apparatus includes a locking device for locking the ejector with respect to the second die assembly in a position where the punch has punched out the workpiece from the unprocessed material. The locking device is configured to release the ejector when the upper and lower die assemblies are opened. When released by the locking device as described above, the ejector is pushed out toward the first die assembly by the urging force of the spring. Accordingly, the workpiece fitted in the second die assembly is ejected.
The locking device disclosed in Japanese Patent No. 5423302 includes a slider provided in the second die assembly. The slider slides between a locking position, where the ejector is locked, and a releasing position, where the lock is released. When the punch punches out the workpiece from the unprocessed material in the clamped state, the slider is pushed by the ejector to move to the locking position. On the other hand, when in the opened state, the urging force of the spring acts from the locking position toward the releasing position. The locking device includes a holding mechanism, which holds the slider when it is slid to the locking position and releases the slider at the locking position. The holding mechanism is arranged outside the upper and lower die assemblies to connect the die assemblies to each other. Also, when the upper die assembly and the lower die assembly are opened with the slider held in the locking position, the holding mechanism operates to release the slider from the locking position in accordance with the opening movement.
In the workpiece manufacturing apparatus, the holding mechanism is arranged outside the upper and lower die assemblies to connect the die assemblies to each other so as to perform the operation of releasing the slider at the locking position in accordance with the opening movement of the upper and lower die assemblies. Therefore, it is necessary to provide a dedicated locking device (holding mechanism) that operates in accordance with the opening movement of each workpiece manufacturing apparatus. For this reason, it is difficult to use a common locking device for multiple manufacturing apparatuses, and the versatility of the locking device is low.